Method of operating a wind turbine system including an energy storage system

A control system for an energy storage system in a wind turbine system, the wind turbine system comprising a wind turbine, a power conversion system operably coupled to a generator and an AC line bus, and an energy storage system coupled to the AC line bus, the energy storage system comprising a transformer, a power converter, and an energy storage device, the energy storage system configured to store and provide power generated by the wind turbine;

• the control system comprising:
• one or more processors and one or more memory devices configured to store instructions that when executed by the one or more processors cause the one or more processors to perform operations, the operations comprising:
• determining one or more operating parameters of the wind turbine system, the one or more operating parameters comprising a grid parameter and a wind parameter, the grid parameter indicative of a status of an electrical grid associated with the wind turbine system;
• determining an operating mode for the wind turbine system based at least in part on the one or more operating parameters;
• and
• controlling the wind turbine system based at least in part on the operating mode;
• wherein controlling the wind turbine comprises controlling an energy flow into or out of the energy storage system coupled to the AC line bus;
• and
• wherein when the wind parameter is less than a threshold and the grid parameter indicates the electrical grid is operating without a fault condition, determining the operating mode for the wind turbine system comprises:
• selecting an integrated storage mode, wherein the integrated storage mode includes at least one of the following operations, based at least in part on the wind parameter, providing power from the wind turbine to the energy storage system, providing power from the energy storage system and the wind turbine to the electrical grid, and providing power from the energy storage system to the electrical grid.

A Doubly Fed Induction Generator (DFIG) wind turbine system, comprising:

• a DFIG comprising a rotor and a stator;
• a rotor bus coupled to the rotor;
• a stator bus coupled to the stator;
• a power conversion system coupled to the rotor bus;
• a line bus coupled to the power conversion system;
• an energy storage system coupled to the line bus;
• the energy storage system comprising a transformer, a power converter, and an energy storage device, the energy storage system configured to store and provide power generated by the DFIG;
• and
• a control system comprising one or more processors and one or more memory devices configured to store instructions that when executed by the one or more processors cause the one or more processors to perform operations, the operations comprising:
• determining one or more operating parameters of the DFIG wind turbine system, the one or more operating parameters comprising a grid parameter and a wind parameter, the grid parameter indicative of a status of an electrical grid associated with the DFIG wind turbine system;
• determining an operating mode for the DFIG wind turbine system based at least in part on the one or more operating parameters;
• and
• controlling the DFIG wind turbine system based at least in part on the operating mode;
• wherein controlling the wind turbine system based at least in part on the operating mode comprises controlling an energy flow into or out of the energy storage system;
• wherein determining an operating mode of the MG wind turbine system comprises selecting an integrated storage mode, a yaw power backup mode, or an e-brake mode;
• and
• wherein when the wind parameter is less than a threshold and the grid parameter indicates the electrical grid is operating without a fault condition, determining the operating mode for the wind turbine system comprises:
• selecting an integrated storage mode, wherein the integrated storage mode includes at least one of the following operations, based at least in part on the wind parameter, providing power from the wind turbine to the energy storage system, providing power from the energy storage system and the wind turbine to the electrical grid, and providing power from the energy storage system to the electrical grid.